Former President Barack Obama's speech in Indonesia in which he warned of "an aggressive kind of nationalism" has drawn both criticism and applause, depending on the politics of who was listening. But it ignited a useful and needed debate on the actual meaning of nationalism.

The word has been thrown around almost forever, and it's a word fraught with ambiguity that demands context, and never more so than in the pugnaciously polarized time of President Donald Trump and social media. The word is pushed and pulled into all manner of shapes and colors like a child's Play-Doh, defined and distorted in the service of ideology.

Trump started the current controversy in his inaugural address, which his many critics decried as dark, divisive and dangerous. But it doesn't have to be any of those things. "Conservatives should embrace a sensible and moderate form of nationalism," write Rich Lowry and Ramesh Ponnuru in National Review. They argue that nationalism can be a healthy and constructive force when shorn of wrong-headed denigration of foreigners and promotion of aggressive warfare.

A benign nationalism can reflect loyalty to one's country, they argue, and "a sense of belonging, allegiance, and gratitude." Such nationalism emphasizes a nation's identity, its people and its culture, an inclusive solidarity that offers no apology for love of country. But raw identity politics, lately so popular in certain precincts, is divisive because it discards the idea of e pluribus unum -- out of many, one. Identity politics fractures and fragments a society; a benign nationalism binds the culture together. It's a matter of emphasis, and an important one at that. Solidarity can be reinforced in the best sense through Fourth of July fireworks, parades, anthems and the flag.

"Surely, the revulsion that most people feel when protesters burn an American flag is based on the belief not that the protesters are symbolically destroying an idea," write Lowry and Ponnuru, "but rather that they are disrespecting the nation to which they owe respect and fealty." Honoring symbols of patriotism; singing "The Star-Spangled Banner"; standing for the presentation of the colors; and cheering the nation's heroes, whether soldiers, astronauts or athletes, are traditions worthy of preserving.

Americans who dissent from this often invoke the words of the late William F. Buckley Jr., their intellectual hero. "I'm as patriotic as anyone from sea to shining sea," he said, "but there's not a molecule of nationalism in me." We usually get a paraphrase of that offered with varying emphasis, depending on whether nationalism and patriotism are cited as Siamese twins, attached at the heart and soul, or two distinctly different things.

Buckley might not appreciate how his remark is manipulated now. Nationalism should not be applied as an all-purpose generalization. In specific application, it is firmly rooted in the nation's democratic values and ideals of America the Beautiful, the land of the free and the home of the brave. It can be an emotional passion as well as an intellectual one; a celebration of the civic, not the ethnic. It's about liberty and the rule of law, a Constitution carefully crafted and cautiously amended to embrace the more perfect union. Martin Luther King Jr. understood this when he wrote "I Have a Dream." That famous speech was almost a sequel to Abraham Lincoln's Gettysburg Address, reprising "Four score and seven years ago" to "Five score years ago," honoring the Emancipation Proclamation.

Irving Kristol, one of the founders of neoconservativism, fused the ideas of patriotism with nationalism. "Patriotism springs from love of the nation's past; nationalism arises out of hope for the nation's future, distinctive greatness" he wrote in his book "Reflections of a Neoconservative" more than three decades ago.

Ronald Reagan was a new kind of Republican who revived the idea of nationalism based on strength and pride of country in the fashion of Theodore Roosevelt. Some thought Trump's being a rough-and-ready outsider would strike a similar appeal. But he disappoints many who want to be his friend with his bluster, bullying braggadocio and scant invitation to the better angels. He ignores the intellectual idealism of the Founding Fathers.

But patriotism and democratic nationalism can enhance each other, as John Fonte, senior fellow at the Hudson Institute, insists. Love of country and pride in the stories handed down from generation to generation create an emotional tradition, as well as a cultural and an intellectual one, with images of George Washington crossing the Delaware River, the Gettysburg Address, the raising of the flag at Iwo Jima and the irresistible moral force of the civil rights movement. The American entrepreneur who created the greatest economy the world has ever known contributes, too. Such patriotic pride, no matter who the president, forged a national identity that is always moving toward that more perfect union. It's an imperfect world, after all, and every little bit helps.